The present invention relates to a technology for obtaining information concerning guidance such as routes by using the description of Markup Language. More particularly, this invention relates to a technology that is applied to a car navigation system, a personal computer, a PDA (Personal Digital Assistant), a mobile telephone terminal (PDC (Personal Digital Cellular)), a PHS terminal (Personal Handyphone System), etc., and utilized for supplying various route information and additional information, such as road guidance, tourism guidance, distribution plans, tour plans, trafficcontrol, scheduling, entertainments and local government services, through a network and electronic media.
In recent years, along with the remarkable development of mobile terminals such as the car navigation system and PDA, it has become possible to obtain various information without any limitation in locations. However, problems have arisen as the saturation level of mobile terminals has increased. For example, the network load increases and the processing load increases in the information supplying service device because of an increase in the amount of traffic. For this reason, there have been strong demands for means and methods for effectively solve the above-mentioned problems.
FIG. 56 is a block diagram that shows a conventional guide information supplying system 10. For example, this guide information supplying system 10 searches for a current position of a guide information requesting device 60 that is installed in a car which is running. When this car has reached a target position (for example, an interchange of an express way or a tourist point), guide information related to the target position (for example, traffic information, tourism information) is supplied to the guide information requesting device 60.
The guide information supplying device 20 is provided with a searching function for searching for the current position of the car in which the guide information requesting device 60 is installed, a matching function for making a matching between the current position informed from the guide information requesting device 60 every predetermined interval of time and a target position on a route through which the car is traveling, and a guide information supplying function for supplying guide information related to the target position at the time when the matching has been made.
These guide information supplying device 20 and guide information requesting device 60 become communicatable through the Internet 30, a traveling object network 40, a radio station 50 and a radio link R. In the guide information supplying device 20, the communication interface 21 serves as an communication interface for the guide information supplying device 20.
A control unit 22 controls respective parts of the guide information supplying device 20 so that the above-mentioned searching function, the guide information supplying function, etc. are achieved. The matching processing section 23 achieves the above-mentioned matching functions. A guide information database 24 is a database that stores pieces of guide information that correspond to target positions respectively placed on a plurality of routes. A storage section 25 stores route information, etc., required for the pursuit for the current position. A bus 26 connects the respective parts of the guide information supplying device 20.
The guide information requesting device 60 is, for example, a car navigation system installed in a car, and provided with functions, such as a current position informing function for informing the guide information supplying device 20 of the current position that changes with time in traveling every predetermined interval of time and a guide information presenting function for presenting the guide information supplied by the guide information supplying device 20 at the time when the car has reached a target position on one of the routes to the driver, etc.
An antenna 61 is provided with a function that transmits and receives electric waves used for carrying out communications with the radio station 50 through the radio link R. The communication interface 62 serves as communication interface to an external device. A control unit 63 controls the respective parts of the guide information requesting device 60 so that the above-mentioned current position informing function, the guide information presenting function, etc. are achieved.
A current position information acquiring section 64 utilizes the GPS (Global Positioning System) so that it acquires the current position information related to the current position represented by the latitude/longitude every fixed interval of time. The GPS, which is an electric wave navigation system developed in the United States, is a system for carrying out three-dimensional measurements, that is, latitude, longitude and altitude, by using not less than four satellites for a positional measurement at one time.
Among the three-dimensional measurements, latitude, longitude, and altitude, the current position information acquiring section 64 uses the information of latitude and longitude as the current position information. A display section 65 is constituted by a LCD (Liquid Crystal Display), etc., so that it displays guide information, map information, etc. A bus 66 connects the respective parts of the guide information request device 60.
In the above-mentioned arrangement, if a car travels from a start point to an end point through a certain route, the control unit 63 of the guide information requesting device 60 transmits the current position information from the current position information acquiring section 64 every fixed interval of time. Thus, the current position information is received by the guide information supplying device 20 through the radio link R, the radio station 50, the traveling body network 40 and the Internet 30 every fixed interval of time.
Based upon the current position information successively received every fixed interval of time, the control unit 22 of the guide information supplying device 20 pursues for the car in which the guide information requesting device 60 is installed. Moreover, the matching section 23 makes a matching between the current position of the car and the target position within the guide information database 24 so that it monitors whether or not the two positions are coincident with each other within a predetermined range of error.
When the car has arrived at the target position on the route (for example, an interchange in an express way), a matching is made between the current position and the target position. For such matching, the control unit 22 acquires guide information related to the target position (for example, traffic information) from the guide information database 24. The control unit 22 transmits the guide information to the guide information requesting device 60.
The guide information is received by the guide information requesting device 60 through the Internet 30, the traveling object network 40, the radio station 50 and the radio link R. Thus, the control unit 63 allows the display section 65 to display the traffic information as guide information.
FIG. 57 is a block diagram that shows an arrangement of a guide information supplying system 70 that shows another conventional structural example. In this figure, those parts corresponding to the respective parts shown in FIG. 56 are indicated by the same reference numerals.
In this guide information supplying system 70, for example, to a guide information requesting device 90 installed in a car in travel is preliminarily downloaded a guide information database 83 that stores guide information respectively related to a plurality of target positions located on a plurality of routes from a guide information supplying device 80, and when there is a match between the current position and the target position on the guide information requesting device 90 side, the corresponding guide information is selected from the guide information database that has been downloaded, and supplied to the driver, etc.
The guide information supplying device 80 has a function for preliminarily supplying a guide information database 83 that stores guide information respectively related to a plurality of target positions located on a plurality of routes to the guide information requesting device 90.
These guide information supplying device 80 and guide information requesting device 90 become communicatable through the Internet 30, a traveling object network 40, a radio station 50 and a radio link R. In the guide information supplying device 80, the communication interface 81 serves as an communication interface for the guide information supplying device 80.
A control unit 82, which controls the respective parts of the guide information supplying device 80, is provided with a function for managing the above-mentioned guide information database 83 and a function for supplying the guide information database 83 to the guide information requesting device 90. The guide information database 83 is a database that stores guide information respectively related to a plurality of target positions located on a plurality of routes. A storage section 84 stores various pieces of information. A bus 85 connects the respective parts of the guide information supplying device 80.
Here, the guide information requesting device 90 is, for example, a car navigation system installed in a car, and provided with functions, such as a current position information acquiring function for acquiring the current position information related to the current position that changes with time in traveling every predetermined interval of time, a matching function for making a matching between the current position and the target position on a route through which the car travels, and a guide information supplying function for supplying guide information related to the target position from the guide information database 83 supplied by the guide information supplying device 80, at the time when the matching has been made.
An antenna 91 is provided with a function that transmits and receives electric waves used for carrying out communications with the radio station 50 through the radio link R. The communication interface 92 serves as a communication interface to an external device. A control unit 93 controls the respective parts of the guide information requesting device 90 so that the above-mentioned guide information supplying function, etc. are achieved.
A current position information acquiring section 94 utilizes the aforementioned GPS so that it acquires the current position information related to the current position represented by the latitude/longitude every fixed interval of time. A storage section 95 stores the guide information database 83 that has been downloaded from the guide information supplying device 80.
Here, in another conventional system, a driver for reading information from a portable-type recording medium is installed in place of the storage section 95 so that the driver reads the portable-type recording medium in which the guide information database 83 has been stored.
A matching processing section 96 has a function for making a matching between the current position corresponding to the current position information acquired by the current position information acquiring section 94 every fixed interval of time and the target position on a route through which the car is traveling. A display section 97, which is constituted by a LCD, etc., displays the guide information, map information, etc. A bus 98 connects the respective parts of the guide information requesting device 90.
In the above-mentioned arrangement, before a car travels from an start point to an end point through a route, the control unit 93 of the guide information requesting device 90 transmits a downloading request for the guide information database 83 to the guide information supplying device 80 through the radio link R, the radio station 50, the traveling object network 40 and the Internet 30.
With this arrangement, the guide information database 83 is downloaded from the guide information supplying device 80 to the guide information requesting device 90 through the Internet 30, the traveling object network 40, the radio station 50 and the radio link R. The downloaded guide information database 83 is stored in the storage section 95 by the control of the control unit 93.
In this state, if a car travels from an start point to an end point through a route, the current position information acquiring section 94 acquires the current position information every fixed interval of time. Moreover, the matching processing section 96 makes a matching between the current position obtained from the current position information and the target position with in the guide information database in the storage section 95 so that it monitors whether or not the two positions are coincident with each other within a predetermined range of error.
When the car has arrived at the target position on a route (for example, an interchange in an express way), the matching is made between the current position and the target position. Therefore, after having acquired guide information (for example, traffic information) related to the target position from the guide information database, the control unit 93 allows the display section 97 to display the traffic information as guide information.
As described above, in the guide information supplying system 10 shown in FIG. 56, the current position of the car is pursued on the guide information supplying device 20 side, and when the car has arrived at the target position, the guide information is supplied to the guide information requesting device 60.
However, in the guide information supplying system 10, in order to carry out the above-mentioned pursuit, the guide information requesting device 60 needs to inform the guide information supplying device 20 of the current position information every predetermined interval of time. Therefore, as the number of cars to be pursued on the guide information supplying device 20 increases, the load of the guide information supplying device 20 increases.
Therefore, in the conventional guide information supplying system 10, in order to reduce the load of the guide information supplying device 20, for example, it is necessary to prepare the guide information supplying device 20 as a high spec machine or to provide a plurality of guide information supplying devices 20 so as to carry out the processes in a dispersed manner, resulting in high production costs.
Moreover, in the conventional guide information supplying system 10, since the current position information is given from the guide information requesting device 60 to the guide information supplying device 20 every fixed interval of time in order to carry out the above-mentioned pursuit, the traffic of the network (the traveling object network 40, the Internet 30) is inevitably increased as the number of cars to be pursued by the guide information supplying device 20 increases, resulting in an increase in the network load.
Moreover, in the guide information supplying system 70 shown in FIG. 57, the guide information database 83 needs to be preliminarily downloaded from the guide information supplying device 80 to the guide information requesting device 90, and when the car has arrived at the target position, the corresponding guide information contained in the guide information database 83 is supplied to the driver.
However, in the method of downloading the guide information database 83, all the pieces of guide information located on the plurality of routes of the guide information database 83 are included in the guide information database 83. Therefore, unless the car travels through all the routes, there are some pieces of guide information that have not been used at all, resulting in wasteful use of data. Moreover, in the conventional guide information supplying system 70, the guide information database 83 having a great capacity needs to be downloaded. Therefore, the resulting problem is that, as the number of simultaneous down-loads increases, the load of the guide information supplying device 80 and the network load increase.
In the above-mentioned method, in place of the method of downloading, a portable-type recording medium having the guide information database 83 is installed on the guide information requesting device 90 side. In this method, it is certainly possible to solve the problems of the increased load of the guide information supplying device 80 and the increased network load.
In the above-mentioned method, however, due to inherent characteristics of the portable-type recording medium, since the recorded information is not updated at real time, other problems arise in which guide information to be supplied to the driver becomes ineffective or different from the actual situation.
It is an object of this invention to provide a method of a device for requesting guide information, a method of a device for supplying guide information which can reduce the network load required for supplying guide information and the load on the guide information supplying device. It is another object of this invention to provide a computer program which when executed on a computer realizes the devices according to the present invention on a computer.
The guide information requesting device according to one aspect of this invention comprises a situation information acquiring unit which acquires current situation information related to a current situation concerning a traveling object every predetermined interval of time; a matching unit which carries out a matching between a normal situation and the current situation, based upon the normal situation information including a sequence of a plurality of predetermined normal situations and the current situation information; a requesting unit which, if there is a match between the normal situation and the current situation, requests an external guide information supplying device to send guide information related to the normal situation, through a network; and a presenting unit which presents the guide information supplied by the guide information supplying device through the network.
According to the above-mentioned aspect, it is not until there is a match between a normal situation and the current situation that a request is given to the guide information supplying device. Therefore, in comparison with the conventional system in which the guide information supplying device is always accessed every fixed interval of time or a database including unnecessary guide information needs to be downloaded, it is possible to reduce the network load and load on the guide information supplying device side.
The guide information requesting device according to another aspect of this invention comprises a current position information acquiring unit which acquires current position information related to a current position concerning a traveling object every predetermined interval of time; a matching unit which carries out a matching between target position information including a sequence of target positions located on a route through which said traveling object shifts and the current position information; a requesting unit which, if there is a match between the target position information and the current position information, requests an external guide information supplying device to send guide information related to the target position, through a network; and a presenting unit which presents the guide information supplied by the guide information supplying device through the network.
According to the above-mentioned aspect, it is not until there is a match between a target position information and the current position information that the guide information supplying device is allowed to request. Therefore, in comparison with the conventional system in which the guide information supplying device is always accessed every fixed interval of time or a database including unnecessary guide information needs to be downloaded, it is possible to reduce the network load and load on the guide information supplying device side.
The guide information supplying device according to still another aspect of this invention comprises a request receiving unit which, if there is match between a current situation related to a traveling object and a predetermined normal situation, receives a request for receiving a supply of guide information related to the normal situation from a guide information requesting device through a network; and a supply unit which, when the request has been accepted, supplies guide information related to the normal situation to said guide information requesting device through the network.
According to above-mentioned aspect, it is not until there is a match between a normal situation and the current situation that the guide information requesting device is allowed to request. Therefore, in comparison with the conventional system in which the guide information supplying device is always accessed every fixed interval of time or a database including unnecessary guide information needs to be downloaded, it is possible to reduce the network load and load on the guide information supplying device side.
The guide information supplying device according to still another aspect of this invention comprises a request receiving unit which, if there is a match between a current position of a traveling object and a target position located on a route through which said traveling object shifts, receives a request for receiving a supply of guide information related to the target position from a guide information requesting device through a network; and a supply unit which, when the request has been accepted, supplies guide information related to the target position to said guide information requesting device through the network.
According to the above-mentioned aspect, it is not until there is a match between a target position and the current position that the guide information requesting device is allowed to request. Therefore, in comparison with the conventional system in which the guide information supplying device is always accessed every fixed interval of time or a database including unnecessary guide information needs to be downloaded, it is possible to reduce the network load and load on the guide information supplying device side.
The computer program according to the present invention realizes the above-mentioned units according to the present invention on a computer.
Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.